During a playdate after Christmas, Woody, Buzz Lightyear, Trixie, and the rest of Bonnie's toys discover an unfamiliar set of action figures called the Battlesaurs. These new toys are highly advanced, believing themselves to be real warriors in an intricate prehistoric-themed world. Trixie, who has always yearned for a more significant role in playtime, is especially enamored by their leader, Reptillus Maximus. As the day unfolds, it becomes apparent that the Battlesaurs are unaware they are toys and have never experienced true playtime. This revelation sets the stage for an unexpected adventure for Woody and his friends.

Trixie struggles with her identity while attempting to help the Battlesaurs realize their true purpose. As conflicts and friendships intermingle, she takes on a pivotal role in bridging the world of the Battlesaurs and the traditional toys. Meanwhile, Woody and Buzz work together to devise a plan to return to Bonnie before she notices their absence, navigating through various challenges posed by the Battlesaurs’ ignorance of their toy nature. The climax brings an intense confrontation where reality meets imagination, forcing all characters to confront their perceptions of self and purpose before they can return to their regular playtime routines.